<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<input type="button" id="qiao" value="点击">
<a href="baidu.com">哈哈</a>
<script>
    // var btn = document.querySelector("#qiao");
    var btn = document.getElementById("qiao");
    btn.addEventListener("click", function () {
        console.log("自行车!");
    })
    var a = document.querySelector("a");
    console.log(a);
</script>

</body>
</html>